I've never understood the fascination with having an instructor be very senior. Some of the worst instructors I've ever had were extremely senior, and some of the best very junior. What matters most is how good they are at teaching, not how long they happen to have been at a particular company. All seniority is good for is determining bid status. It doesn't relate to experience or qualification in any way, and that's by design.

Maybe I'm new age, but I think ability to teach should be the biggest reason to hire someone as an instructor. There are plenty of crusty old captains who are good pilots, but couldn't teach if their lives depended on it.

That being said I do think there is value in having the instructor force be line seniority pilots so they can relate to line flying directly.